1. Field of the Invention
This invention relates to an electronic system and more particularly to an electronic system such as a computer system having a chassis capable of accommodating both redundant and nonredundant power supply configurations.
2. Description of the Related Art
Electronic systems such as computer systems employ power supplies to convert generally readily available time varying alternating current (AC) voltage levels to approximately zero frequency direct current (DC) voltage levels of, for example, 12 Volts (V), 5 V, and 3.3 V. The electronic systems utilize the DC voltages to operate electronic circuitry such as mother boards, disk drives, and peripheral circuit boards.
Some electronic systems are sold with nonredundant power supply configurations. Nonredundant power supply configurations are typically used in lower cost systems where power supply failure is generally more of an inconvenience than a catastrophic event. Nonredundant power supply configurations are generally divided into single power supply and multiple power supply configurations. In the single power supply, nonredundant configuration, a single power supply supplies all power requirements and connects to electronic circuitry such as the mother board and disk drives.
In the multiple power supply, nonredundant configuration, the electronic system requires P watts of power, and N power supplies each provide approximately 1/N times P watts of power, where N is an integer and P is a real number. Thus, if one of the N power supplies fails, the electronic system will fail as the remaining N-1 power supplies cannot provide the complete power requirements. The N power supplies each have connectors that are specially designed for connection to a power supply `paralleling circuit board` rather than directly to electronic circuitry. The paralleling circuit board approximately evenly divides the electronic system current load among the N power supplies. The paralleling circuit board is securely fixed to a chassis of the electronic system using, for example, screws, and connected to the electronic circuitry to route power to the electronic system.
In the redundant power supply configuration, multiple power supplies are typically also connected via the specially designed connectors to a paralleling circuit board. However, each of the N power supplies are capable of supplying at least 1/(N-1) times P watts of power. If a power supply fails, the paralleling circuit board takes the failed power supply off line and allows the remaining functional N-1 power supplies to continue approximately evenly sharing the electronic system power requirements.
Some conventional systems have nonredundant to redundant power supply configuration upgrade capability. These upgradeable systems are manufactured with the paralleling board securely fixed to the chassis and M power supplies connected to the paralleling board to each supply 1/M times P watts of power to the electronic system, where M is an integer equal to at least one and P is again the electronic system power requirement. The M power supplies are disposed within respective bays in the chassis, and additional vacant bays are provided in the event that the electronic system is upgraded to a redundant power supply configuration. The electronic system can be upgraded to a redundant power supply configuration by installing one or more power supplies into the vacant bays and connecting them to the paralleling circuit board so as to approximately evenly share power requirements.
The upgradeable electronic system is more expensive than a comparable nonupgradeable nonredundant power supply configured electronic system because of the added cost of the paralleling board. Thus, in the event that the electronic system is not upgraded, the upgradeable electronic system is equivalent to the nonupgradeable nonredundant power supply configured electronic system but costs more.
Additionally, servicing a group of electronic systems can be more difficult and costly when the group includes nonredundant single power supply configured electronic systems that do not include a paralleling board and nonredundant and redundant power supply configured electronic systems that include a paralleling board. Because the wiring harnesses of the power supplies that connect directly to electronic circuitry and the wiring harnesses of the power supplies that connect directly to the paralleling board are different, two distinct types of power supplies may be necessary to service the group. Although the two distinct types of power supplies may be equivalent in manufacturing cost, it typically costs more to manufacture and track two different types of power supplies than to manufacture a single power supply type.
Thus, a more cost effective electronic system with improved serviceability is desirable.